Oldham C 1100 Manuel Technique page 17

Instantaneous CO
The instantaneous CO
never exceed recommended short term exposure limit values. The instantaneous CO
concentration is also indicated with the five LEDs below the display. Immediately leave the
area if the second yellow LED is lit and the buzzer sounds!
Alarm functions (factory settings):
LED
Green 1: always lit when the unit is on
Green 2: >0,1 %
Yellow 1: >0,5 %
Yellow 2: >1,5 %
Red: >3,0 %
When the CO concentration exceeds 1,5 %
2
the buzzer beeps intermittent. If the CO
lit and the buzzer sounds continuously. By pushing the button (alarm acknowledgement) the
buzzer temporarily will be turned off. The backlight is automatically turned on at pre and
main alarm and turned off 8-16 seconds after alarm acknowledgement. If the alarm condition
remains 5 minutes from alarm acknowledgement the buzzer becomes actuated again. When
the alarm condition has vanished the C 1100 returns to normal operation with the buzzer
silenced (- if not acknowledged the backlight will remain on).
The TWA Value
8 hours TWA (Time Weighted Average) value represents the average carbon dioxide level
exposure during a working day. In most European countries the CO
hours/day or 40 hours/week) is set to 0,5 %
term to be exposed to more than this value during an 8-hour working day.
The TWA value is shown in the lower part of the display. At power on the TWA-value starts
from 0,04% CO and accumulates current carbon dioxide levels averaged over time. Data
2
acquisition is done every 4
During continuous operation the TWA value displayed by the C 1100 unit is an average value
of the latest 8 hours data recorded. To reset TWA, just switch the unit into Off Mode and back
on (without any battery charger connected). C1100 then starts up with the default value 0,04
% CO .
VOL 2
In CALb, the current TWA-value is kept on hold. This is useful when you want to take a
pause in measuring, for example, if you are doing a worksite investigation and have to leave
the area for some time. When the unit is switched back into On Mode it will resume the
started TWA recording period.
Switching the unit into OFF Mode, with the battery charger connected until switched back
into ON Mode again, will also pause and resume the TWA calculations.
Concentration
2
concentration is shown in the upper part of the display and should
2
(Recommended indoor max CO
VOL
VOL
, Buzzer (bip-bip-bip-...), pre alarm.
VOL
, Buzzer (biiiiiiiiiiii....), main alarm.
VOL
concentration rises above 3,0 %
2
th
minute for the passed 4 minutes average exposure.
concentration level)
2
the second yellow LED is lit (pre alarm) and
VOL
(5000 ppm). It is considered unhealthy long-
VOL
2
the red LED is
VOL
hygienic limit value (8
2
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